Merge pull request #313 from verypurple/patch-1

Update memory-guide.md

Author: jhansson-ard

content/learn/03.programming/06.memory-guide/memory-guide.md

@@ -411,7 +411,7 @@ The following table shows basic value data types in Arduino:
 |     **Type**    | **Byte Length** |       **Range of Values**       |
 |:---------------:|:---------------:|:-------------------------------:|
 |    `boolean`    |        1        | Limited to logic true and false |
-|      `char`     |        1        |           -128 to 128           |
+|      `char`     |        1        |           -128 to 127           |
 | `unsigned char` |        1        |             0 to 255            |
 |      `byte`     |        1        |             o to 255            |
 |      `int`      |        2        |        -32,768 to 32,767        |
@@ -447,4 +447,4 @@ Memory architectures in microcontroller-based systems is a pretty vast topic; if
 
 [1] S. F. Barrett and D. J. Pack, Microchip AVR® Microcontroller Primer: Programming and Interfacing, Third Edition (Synthesis Lectures on Digital Circuits and Systems), Morgan & Claypool, 2019. <br />
 [2] J. Y. Yiu, The Definitive Guide to ARM Cortex -M0 and Cortex-M0+ Processors, Second ed., Newnes, 2015.<br />
-[3] J. Yiu, The Definitive Guide to ARM® Cortex®-M3 and Cortex®-M4 Processors, Third ed., Newnes, 2014.<br />
+[3] J. Yiu, The Definitive Guide to ARM® Cortex®-M3 and Cortex®-M4 Processors, Third ed., Newnes, 2014.<br />